class DateUtils{

  static String getNowDateStr(){
    var now=DateTime.now();//获取当前时间
    return '${now.year}-${now.month}-${now.day}';
  }
  static String getMonthDateStr(){
    var now=DateTime.now();//获取当前时间
    var first = DateTime(now.year, now.month, 1);
    return '${first.year}-${first.month}-${first.day}';
  }
  static String get30DateStr(){
    var now=DateTime.now();//获取当前时间
    var old30 = DateTime(now.year, now.month, now.day - 30);
    return '${old30.year}-${old30.month}-${old30.day}';
  }
}